Gamma is a float value, with 1.0 being neutral.
The offset and saturation are the black and white levels, integer range
0...255.
You can use the levels to make the pictures lighter and darker, the gamma to
increase details on either the brighter or the darker part.

Jörg

> I'm not too sure, I haven't seen any documentation on it either. Run
> halftone from a command line without options to get the defaults, but as
> for which direction or range...got me.
>
> John
>
> On Wed, 17 Mar 2004 14:46:31 -0500, Green, Tom <TGreen_at_CWF.org> wrote:
>
> > One more question on the video conversion if I may...
> >
> > What is the range of numbers to enter for "gamma" and "saturation" and
> > which direction makes which changes?
> >